Wearable devices continue to increase in popularity. For example, wrist-worn fitness trackers record and display a user's steps taken over the course of a day. Other devices record accelerometer measurements and alert a medical professional to a possible fall event for older patients.
However, wearable devices usually include a single gyroscope or inertial measurement unit (IMU). Accordingly, measurements usually suffer from low accuracy and drift. Some solutions include the use of expensive and large laboratories that use more accurate visual analysis to avoid errors inherent in wearable components. However, such solutions are impractical for most uses and cannot scale.
Moreover, many existing calculations regarding balance (e.g., deviations from plumb) are rough and fail to account for how human reflexes function. In particular, minor yet rapid deviations from plumb are over-weighed in extant models even through such reflexes represent normal balancing techniques.